Tech Support for OAuth E-Mail changes
Earlier this year my e-mail just stopped working. I would connect and it wouldn't authenticate. So I called tech support. This happened a couple of times, and my e-mail would be down for up to a week before they fixed anything.
The encounters with tech support were frustrating. They kept referring me to the web based email on the ATT website, or suggesting that I "get the app", or that I had a problem with my e-mail client. This was all a waste for time, since it was clear that something had changed with your servers that they didn't know about.
I ultimately figured out that the problem was the new OAuth changes. I went through the procedure and fixed it myself. None of the suggestions by your tech support pointed me toward this solution. They didn't know about OAuth at all.
Now, more recently, a good friend of mine was frantically hunting me down for help because her e-mail stopped working. She had already called your tech support and also Microsoft's tech support. neither helped. Your support still knew nothing and Microsoft tried to sell her Office365. I connected to her via Team Viewer and walked her through the OAuth changes, which basically assign a new password for the e-mail client.
My point: YOUR TECH SUPPORT DOESN'T KNOW ANYTHING ABOUT THE REQUIRED OAUTH CONFIGURATIONS, WHICH ARE NEEDED BY ANYONE USING A DESKTOP CLIENT TO ACCESS THEIR E-MAIL.